C* SUBROUTINE SURFBOXW(AREA,REFL,DIFU,ABSP,AREA2,REFL2,DIFU2, 1 ABSP2,REFLIR,DIFUIR,ABSPIR,ABSNCFVI,ABSNCFIR, 2 NCFVEC,ATTSURF,FORCE) CC CC NAME : SURFBOXW CC CC PURPOSE : COMPUTES THE FORCE IN THE SATELLITE SURFACES, FOR A GIVEN RADIATION VECTOR CC CC PARAMETERS : CC IN : AREA(I,J) : AREAS OF FLAT SURFACES [m^2] CC REFL(I,J) : REFLEXION COEFFICIENT CC DIFU(I,J) : DIFFUSION COEFFICIENT CC ABSP(I,J) : ABSORPTION COEFFICIENT CC I = 1 +Z (TOWARDS THE EARTH) CC I = 2 +Y (ALONG SOLAR PANELS BEAMS) CC I = 3 +X (ALONG BUS DIRECTION ALWAYS ILLUMINATED BY THE SUN) CC I = 4 SOLAR PANELS CC J = 1 POSITIVE DIRECTION CC J = 2 NEGATIVE DIRECTION CC ????2(I,J) : INDEX 2 INDICATES AREAS AND OPTICAL PROPERTIES OF CYLINDRICAL CC SURFACES, SAME MEANING OF (I,J) AS BEFORE CC ????IR(I,J ): OPTICAL PROPERTIES IN THE INFRARED, NO SEPARATION CC BETWEEN FLAT AND CYLINDRICAL SURFACES CC ABSNCFVI : MAGNITUDE OF INCIDENT VISIBLE RADIATION [N/m^2] CC ABSNCFIR : MAGNITUDE OF INCIDENT INFRARED RADIATION [N/m^2] CC NCFVEC : UNITARY INCIDENT RADIATION VECTOR IN INERTIAL REFERENCE FRAME CC ATTSURF(K,I): ATTITUDE VECTORS OF SATELLITE SURFACES CC K = 1,2,3 VECTOR COMPONENTS IN INERTIAL REFERENCE FRAME CC I = 1 +Z (TOWARDS THE EARTH) CC I = 2 +Y (ALONG SOLAR PANELS BEAMS) CC I = 3 +X (ALONG BUS DIRECTION ALWAYS ILLUMINATED BY THE SUN) CC I = 4 SOLAR PANELS CC CC OUT : FORCE : RESULTING FORCE VECTOR [Newtons] IN INERTIAL REFERENCE FRAME CC CC AUTHOR : C.J. RODRIGUEZ-SOLANO CC rodriguez@bv.tum.de CC CC VERSION : 1.0 (OCT 2010) CC CC CREATED : 2010/10/18 CC C* IMPLICIT NONE C INTEGER*4 K,I INTEGER*4 SIDE(4) C REAL*8 ABSNCFVI,ABSNCFIR,PI REAL*8 FACABDI,FACREFL REAL*8 NCFVEC(3),FORCE(3) REAL*8 ATTSURF(3,4),NORVEC(3,4) REAL*8 AREA(4,2),REFL(4,2),DIFU(4,2),ABSP(4,2) REAL*8 AREA2(4,2),REFL2(4,2),DIFU2(4,2),ABSP2(4,2) REAL*8 REFLIR(4,2),DIFUIR(4,2),ABSPIR(4,2) REAL*8 COSANG(4) REAL*8 TABSP(3),TREFL(3),TDIFU(3) REAL*8 TABSP2(3),TREFL2(3),TDIFU2(3) REAL*8 PRT_FLT(3,3),PRT_CYL(3,3),PRT_FLTIR(3,3),PRT_CYLIR(3,3) REAL*8 FVI_FLT(3),FVI_CYL(3),FIR_FLT(3),FIR_CYL(3) REAL*8 FVI(3),FIR(3) integer*4 cnt data cnt / 0 / C Initialization of variables PI = 4D0*DATAN(1D0) FORCE(1) = 0D0 FORCE(2) = 0D0 FORCE(3) = 0D0 C -------------------------------- C ANGLE BETWEEN FORCE AND SURFACES C -------------------------------- SIDE(1) = 1 SIDE(2) = 1 SIDE(3) = 1 SIDE(4) = 1 DO K=1,4 COSANG(K) = ATTSURF(1,K)*NCFVEC(1)+ATTSURF(2,K)*NCFVEC(2) 1 +ATTSURF(3,K)*NCFVEC(3) IF(COSANG(K).GE.0D0)THEN SIDE(K) = 2 NORVEC(1,K) = ATTSURF(1,K) NORVEC(2,K) = ATTSURF(2,K) NORVEC(3,K) = ATTSURF(3,K) ELSEIF(COSANG(K).LT.0D0)THEN SIDE(K) = 1 NORVEC(1,K) = -ATTSURF(1,K) NORVEC(2,K) = -ATTSURF(2,K) NORVEC(3,K) = -ATTSURF(3,K) ENDIF ENDDO C -------------------------------------- C FORCE ACTING ON THE SATELLITE SURFACES C -------------------------------------- DO K=1,4 FACABDI = DABS(COSANG(K)) FACREFL = COSANG(K)**2 DO I=1,3 TABSP(I) = FACABDI*NCFVEC(I) TABSP2(I)= TABSP(I) TREFL(I) = (2D0)*FACREFL*NORVEC(I,K) TREFL2(I)= (4D0/3D0)*FACREFL*NORVEC(I,K) TDIFU(I) = FACABDI*(NCFVEC(I)+(2D0/3D0)*NORVEC(I,K)) TDIFU2(I)= FACABDI*(NCFVEC(I) +(PI/6D0)*NORVEC(I,K)) C SATELLITE BUS, INCLUDES DIFFUSE THERMAL RE-RADIATION IF(K.LE.3)THEN PRT_FLT(1,I) = TDIFU(I)*(ABSP(K,SIDE(K))+DIFU(K,SIDE(K))) PRT_FLT(2,I) = TREFL(I)*REFL(K,SIDE(K)) PRT_FLT(3,I) = 0D0 PRT_CYL(1,I) = TDIFU2(I)*(ABSP2(K,SIDE(K)) 1 +DIFU2(K,SIDE(K))) PRT_CYL(2,I) = TREFL2(I)*REFL2(K,SIDE(K)) PRT_CYL(3,I) = 0D0 PRT_FLTIR(1,I) = TDIFU(I)*(ABSPIR(K,SIDE(K)) 1 +DIFUIR(K,SIDE(K))) PRT_FLTIR(2,I) = TREFL(I)*REFLIR(K,SIDE(K)) PRT_FLTIR(3,I) = 0D0 PRT_CYLIR(1,I) = TDIFU2(I)*(ABSPIR(K,SIDE(K)) 1 +DIFUIR(K,SIDE(K))) PRT_CYLIR(2,I) = TREFL2(I)*REFLIR(K,SIDE(K)) PRT_CYLIR(3,I) = 0D0 C SOLAR PANELS, THERMAL RE-RADIATION ALMOST CANCELS (FRONT AND BACK) ELSEIF(K.EQ.4)THEN PRT_FLT(1,I) = TABSP(I)*ABSP(K,SIDE(K)) PRT_FLT(2,I) = TREFL(I)*REFL(K,SIDE(K)) PRT_FLT(3,I) = TDIFU(I)*DIFU(K,SIDE(K)) PRT_CYL(1,I) = TABSP2(I)*ABSP2(K,SIDE(K)) PRT_CYL(2,I) = TREFL2(I)*REFL2(K,SIDE(K)) PRT_CYL(3,I) = TDIFU2(I)*DIFU2(K,SIDE(K)) PRT_FLTIR(1,I) = TABSP(I)*ABSPIR(K,SIDE(K)) PRT_FLTIR(2,I) = TREFL(I)*REFLIR(K,SIDE(K)) PRT_FLTIR(3,I) = TDIFU(I)*DIFUIR(K,SIDE(K)) PRT_CYLIR(1,I) = TABSP2(I)*ABSPIR(K,SIDE(K)) PRT_CYLIR(2,I) = TREFL2(I)*REFLIR(K,SIDE(K)) PRT_CYLIR(3,I) = TDIFU2(I)*DIFUIR(K,SIDE(K)) ENDIF C TOTAL FORCE COMPUTATION FVI_FLT(I) = PRT_FLT(1,I) + PRT_FLT(2,I) + PRT_FLT(3,I) FVI_CYL(I) = PRT_CYL(1,I) + PRT_CYL(2,I) + PRT_CYL(3,I) FIR_FLT(I) = PRT_FLTIR(1,I)+ PRT_FLTIR(2,I)+ PRT_FLTIR(3,I) FIR_CYL(I) = PRT_CYLIR(1,I)+ PRT_CYLIR(2,I)+ PRT_CYLIR(3,I) FVI_FLT(I) = FVI_FLT(I)*AREA(K,SIDE(K)) FVI_CYL(I) = FVI_CYL(I)*AREA2(K,SIDE(K)) FIR_FLT(I) = FIR_FLT(I)*AREA(K,SIDE(K)) FIR_CYL(I) = FIR_CYL(I)*AREA2(K,SIDE(K)) FVI(I) = (FVI_FLT(I)+FVI_CYL(I))*ABSNCFVI FIR(I) = (FIR_FLT(I)+FIR_CYL(I))*ABSNCFIR FORCE(I) = FORCE(I) + FVI(I) + FIR(I) if( cnt.eq.0 ) then C print *,'FORCE ',i,k, FORCE(I), FVI(I),FIR(I) C print *,'FVI ',i,k, FVI_FLT(I), FVI_CYL(I), ABSNCFVI C print *,'FIR ',i,k, FIR_FLT(I), FIR_CYL(I), ABSNCFIR C print *,'FVI_FLT ',i,k, FVI_FLT(I), PRT_FLT(1,I), C . PRT_FLT(2,I), PRT_FLT(3,I), AREA(K,SIDE(K)), SIDE(K) endif ENDDO ENDDO cnt = cnt + 1 END SUBROUTINE